Viewpoint: leaving the "empty glass" of problem-based learning behind: new assumptions and a revised model for case study in preclinical medical education.

The popularity of problem-based learning (PBL) reflects medical educators' recognition that case study can enhance the preclinical medical school curriculum. However, the PBL method itself has features, particularly its reliance on small-group work with tutor-facilitators, that are expensive to implement and that limit the potential educational value of case study. The author systematically analyzes specific aspects of the PBL methodology and concludes that the PBL approach misuses the faculty, tends to compromise the authenticity of cases, and results in an unnecessarily varied and impoverished educational experience for students. Approaches to case study with different assumptions need to be devised. A model is proposed that shifts the goal of case study from development of problem-solving skills to development of ideas that allow meaningful engagement in sophisticated discussions of medicine. In this model, the method shifts from self-directed learning to independent study guided by the expertise of the faculty. One possible approach to case study based on this model is briefly described. It consists of reading published cases from the medical literature, with analysis and discussion of the cases led by faculty experts in large-group format. The approach immerses students in an authentic, state-of-the-art discussion of medicine and is easily incorporated into any curriculum structure at limited cost. The author argues that, contrary to the claims of proponents, the glass is "mostly empty" for PBL and that we can generate the higher-level discussion that case study merits only by moving away from PBL's extraneous assumptions.

IgA nephropathy in a patient with chronic granulomatous disease.

We report the first documented case of X-linked chronic granulomatous disease (CGD) in association with IgA nephropathy in a 22 year old male with multiple soft tissue abscesses. The case highlights the potential role of staphylococcal infections in the pathogenesis of IgA nephropathy and suggests the hypothesis that the neutrophil defect in CGD predisposes to such infections which may trigger IgA immune complex formation.

Oxygen metabolites and hypoxic renal injury: effect of mitochondrial electron transport blockade.

Isolated perfusion of the rat kidney causes hypoxic damage in the cells of the thick ascending limb of the loop of Henle. The cell damage is driven by active solute transport, which generates an imbalance of oxygen supply and demand. This injury is paradoxically prevented by adding the mitochondrial electron transport inhibitors rotenone or antimycin to the perfusion media. The present study shows that rotenone and antimycin decrease production of hydrogen peroxide in the thick ascending limb during perfusion. The findings support the hypothesis that the injury in this model is dependent on mitochondrial electron flow and suggest that mitochondrial electron flow, driven by the work of active solute transport in the presence of limited oxygen availability, may result in the generation of toxic oxygen metabolites.